A Case Report and Literature Review

Case Presentation

A 27-year-old woman (height 165 cm; weight 92 kg) was admitted to hospital for management of a 1.8 cm × 1.3 cm × 1.7 cm renal mass in the lower pole of the right kidney (examined by MRI) and scheduled for laparoscopic partial nephrectomy under general anesthesia. The patient mentioned she had no other medical history but congenital asymptomatic platybasia. The laboratory examinations were normal except uric acid 425 μmol/L (the normal range is 90–360 μmol/L). There was no abnormity for electrocardiogram (ECG) or chest X-ray.

On the operating day, the patient entered the operating room without premedication. ECG, SpO2, end-tidal carbon dioxide pressure (PetCO2) and bispectral index (BIS) were monitored. A 20G catheter was inserted into her left radial artery to ensure real-time blood pressure monitoring. Anesthesia was induced with remifentanil (target-controlled infusion at effect-site concentration of 3 ng/mL), 150 mg propofol and 50 mg rocuronium. A 7 mm ID endotracheal tube was intubated with an insertion distance of 21 cm at the incisors. The patient was ventilated with volume controlled ventilation mode (setting tidal volume at 500 ml, respiratory rate at 12 times/min, inspiration and expiration ratio at 1:2) and was placed in the left lateral decubitus position. Before pneumoperitoneum, airway pressure was controlled within 20 cmH2O and PetCO2 was controlled between 31 and 35 mmHg. Anesthesia was maintained with intravenous remifentanil (target-controlled infusion at effect-site level of 2–3 ng/mL), propofol (constant infusion), and 60% nitrous oxide balanced with oxygen. Sufentanil (totally 20 μg) and cisatracurium (totally 2 mg) was intermittently injected intravenously and the infusion speed of propofol was adjusted according to BIS within the range of 40 to 60.

The procedure was uneventful though there was an episode. After finishing the first trocar portal, a balloon, made from a sutured latex glove, was used to inflate and dilate retroperitoneum cavity. But the balloon was ruptured during inflation and the suture on the balloon was left in retroperitoneum space. Finally, the suture was found and removed after a period of searching with the help of laparoscopy. Procedure was performed via 3 successfully established trocar portals. The retroperitoneal space was hydrostatically dilated and CO2 was insufflated to a pressure of 14 mmHg. During the procedure, the airway pressure increased to 30 cmH2O and PetCO2 was elevated to 41 mmHg. SpO2 remained 100%. We adjusted tidal volume to 550 ml and respiratory rate to 13 times/min. At the end of the surgery, the retroperitoneal carbon dioxide was retreated and airway pressure decreased to 23–24 cmH2O. Operative duration was almost 90 min, during which the hemodynamic parameters were stable. We stopped all intravenous anesthetics and changed the gas supply to 100% O2 with a flow rate of 5 L/min. The patient woke up quickly and could respond to instructions. Then the patient was placed to supine position. Mechanical ventilation was ceased and the patient had spontaneous breathing. Antagonists of muscle relaxant (neostigmine 2 mg plus atropine 1 mg) were given. Two minutes after the stop of mechanical ventilation, SpO2 decreased rapidly to 30% and blood pressure decreased from 120/79 mmHg to 93/65 mmHg. The patient was unconscious. We conducted manual ventilation immediately and then SpO2 returned to 85–90%. Meanwhile, blood pressure recovered. Immediate auscultation showed decreased breath sounds on the right side of chest and the left side was normal. Immediate arterial blood gas analysis showed PCO2 75 mmHg, PO2 83 mmHg. We woke up the patient and she could breathe spontaneously with better tidal volume. We extubated her endotracheal tube and provided oxygen via facemask. She was able to breathe without distress but felt right chest pain. SpO2 climbed to 91–93% gradually. Point-of-care chest X-ray was performed, demonstrating a large, right pneumothorax occupying 70% of the hemithorax (Figure 1).

The patient was transferred to post-anesthesia care unit and stayed for 1 h with facemask oxygen inhalation (oxygen flow rate 5 L/min). Her vital signs were normal during the period and SpO2 returned to 100%. She felt right chest pain relieved a bit. Arterial blood gas was re-examined and all parameters were in normal range. The patient was later sent back to general ward.

In general ward, respiratory and hemodynamic parameters of the patient remained stable during hospital stay. Chest X-ray taken on the first post-operative day revealed complete re-expansion of the right lung (Figure 2). She claimed no chest pain and no other symptoms. The patient was discharged home on postoperative day 5.

Authors and Disclosures

Authors' contributions WQF were responsible for obtaining the patient's informed consent, collecting the data of the patient, follow up, and preparation of the manuscript; ZH participated in the anesthesia and care of the patient and was responsible for revision of the manuscript. All authors read and approved the final manuscript.

Competing interests The authors declare that they have no competing interests.